One of the major problems to be addressed in any multiple robot system is the problem of the collision of a robot arm with another robot arm. Still another problem, faced even in a single robot system, is that of an arm colliding with a fixed obstacle, such as a parts feeder or a part already mounted upon the workpiece during a previous operation.
One of the important advantages of a robot automation work station is its throughput, that is, the amount of work it can perform in a given time and space. Present day robot systems have attempted to increase throughput by making the robot move and/or work faster. Present day robot systems attempt to prevent the occurrence of collisions by comparing the anticipated move of each device sequentially with every other device in an effort to recognize the collision and determine its source. This is unnecessarily time consuming and is further unnecessarily complicated.